Class Project Final: Need some Info, Suggestions

[computergeek13]

I am currently in my 3rd quarter at a technical college, working on a computer science degree in networking security. One of my classes this quarter as a final project rather than exam, has given us the task of designing a full network for a company.

While i can grasp most of the equipment needed, switches, routers, cabling, i have never done nor played with any of the equipment so current speeds, up to date equipment is not part of my knowledge to date.

That is why i turned here, to take some from your expertise, and learn a bit more at the same time. I think that is what this project entrusted us to do.

I saw a similar thread already, however it focused more on pricing than equipment, and i think the poster had a better general idea of what he needed than I.

Here are the details of project
Cost is no object, design a full network for a bio-gen company consisting of 2 floors and 3 main halls.

The middle of the floorplan is a hexagon atrium that connects 3 hallways, A, B, and C.
Each hallway has 12 rooms. Halls A and B have two floors. Hallways A and B have 2 labs each, on each floor that must have seperate feeds than the offices. The atrium must have wireless access. Each hallway is 200' and the atrium is 160' across.

Our instructor said the main internet feed should have a fiber backbone, and allow all computers high speed access to the internet.

Each hallway and each floor needs a seperate subnet. thats 5 subnets, and would the wireless atrium have its own subnet too? perhaps 6 subnets? we are given one class C ip to workwith.

All traffic to each hall should be isolated (switched). All machines able to share files across the network.

Include security and backup measures, and remote admin possibilities.

Each occupied room should have a networked printer as well. ( 46 printers)

Future expansion should be built in (ability to add machines, bandwidth, etc)

Ok, so thats pretty much all the guidelines.

I have to design it in Microsofts Visio, which i have never used but will figure out the toughest part for me is the actual units.

What type of switches?

I guess i need to learn mostly what kind of speeds switches come with for high speed access - what the fiber backbone handles -- and if my initial config stands up to speculation.

**edited out information solved in later posts

I will post back in a few hours after class. Thank you in advance. While i feel i don't know enough to finish this project completely i am excited to learn what seems to be an interesting project
through to fruition.

 

[jeffmoss26]

Well for one thing we don't serve as a place to do your homework for you. That being said however, you do not need routers in every closet. You would have a core switch in a central MDF and have fiber run out to each of your closets (IDF). Normally one or two IDF's per floor, then if you want the computer labs to have their own switch that would be an additional IDF. You would want switches with gigabit fiber cards in them.
To be honest I think you have a lot more learning to do on how networks are designed, different topologies, etc. I think you are confusing physical connections with theoretical applications in networks. A subnet is just a group of IP addresses. All you need is one router, that is from your internet connection going into your LAN.

Jeff

 

[computergeek13]

thank you for the response jeff, i wasnt asking anyone to do my homework - i want to learn this - but it is my first year back to college and this is my first networking class. It is week 7 now and all i know about switches and routers, hubs and cables, come from the first 6 weeks.

Ok do what kind of line do businesses use to supply their main closet?

Would that be like a T1 line? or is that too slow for this many computers? What would be fast er and to quote instructor " able to provide each machine with high speed internet fed from a fiber backbone" again price is no cost.

So say for now that T1 comes into the MDF - first it will go to the router, then to a switch. Would a Cisco switch that has 24 10/100/1000 ports be good? Why are there 3 speeds listed? Can each port be configured to run slower speeds to save bandwidth?
From that Cisco switch - i run fiber to each floors IDF, and each Labs IDF. In the IDF i have another switch - that runs Cat5e ethernet cable to each machines NIC.

Is that correct?

I understand you do not want to do my homework, do you have a good place for me to begin reading if you feel morally obligated to decline help?

i do appreciate your help with this - i will try looking for some other sources of information in the meantime.

 

[computergeek13]

also i tried to look up some info on what else i need in the closets.
Like backup UPS devices, or machines in the closets to to manage the server.

what is normally put in server's closets?

 

[Malk-a-mite]

this is my first networking class. It is week 7 now and all i know about switches and routers, hubs and cables, come from the first 6 weeks.

funny.... "has given us the task of designing a full network for a company." That sounds just like a capstone class at a couple of universities, not the first class.

 

[Doliviss]

I concur. This isn't a first level networking final, and if it is, that instructor should be beaten.

That was the final I had in my 2 year CCNA course(s) when I took it back in high school. It still kicked our ass after 2 years studying the stuff.

 

[Orinthical]

thank you for the response jeff, i wasnt asking anyone to do my homework - i want to learn this - but it is my first year back to college and this is my first networking class. It is week 7 now and all i know about switches and routers, hubs and cables, come from the first 6 weeks.

Ok do what kind of line do businesses use to supply their main closet?

Would that be like a T1 line? or is that too slow for this many computers? What would be fast er and to quote instructor " able to provide each machine with high speed internet fed from a fiber backbone" again price is no cost.

So say for now that T1 comes into the MDF - first it will go to the router, then to a switch. Would a Cisco switch that has 24 10/100/1000 ports be good? Why are there 3 speeds listed? Can each port be configured to run slower speeds to save bandwidth?
From that Cisco switch - i run fiber to each floors IDF, and each Labs IDF. In the IDF i have another switch - that runs Cat5e ethernet cable to each machines NIC.

Is that correct?

I understand you do not want to do my homework, do you have a good place for me to begin reading if you feel morally obligated to decline help?

i do appreciate your help with this - i will try looking for some other sources of information in the meantime.

If cost is no option, look at an OC48 connection. Something more realistic for a private company would be a T3 though.

Primary demarc to perimeter firewall solution(s) to some sort of core switch - look at the higher end cisco switches - we're talking enterprise not a "I'll throw a 24 port gigabit switch in there" type of scenario. Look at two 6x00 series switches, or better, with a 10GB ISL between them for your core. Expand outwards with 2GB Trunks (2 fiber 1GB lines, trunked) to your other switches, each returning to the core switch. This is referred to as a "star topology." For each spoke (hall closets) you should be looking at managed 48Port Gigabit switches. Each lab can then have a number of wall jacks installed or individual patch panels that run back to the hall closets.

The only reason I can think that he may be giving you something like this so soon, if this is indeed as early in your class as you say it is, is to gauge the classroom's knowledge level. If that is the case than you would be doing yourself an injustice by "pretending" to know more than you do, by seeking design help here or anywhere else. Level-setting is important for proper classroom development. Take these tidbits and do a little googling, you're sure to find some Cisco datacenter guides out there.

Oh and please - some of the first steps are to cover the basics. Look at the difference between managed, unmanaged, PoE, enterprise, datacenter, trunking, ISL, fiber (multi or single), connectivity options and arguably most important - Spanning Tree.

 

[xphil3]

I
Look at two 6x00 series switches, or better, with a 10GB ISL between them for your core. Expand outwards with 2GB Trunks (2 fiber 1GB lines, trunked) to your other switches, each returning to the core switch. This is referred to as a "star topology." For each spoke (hall closets) you should be looking at managed 48Port Gigabit switches. Each lab can then have a number of wall jacks installed or individual patch panels that run back to the hall closets.

Im just going to step in real quick and give my .02

Everything that Orinthical said is spot on, this may be to gauge your overall skill level and "stretching" the truth may not be something that you want to do in this case. To the OP, Orinthical just explained the core elements of a very specific standard topology, do you know what its called? If you don't I would highly recommend that you don't over stretch the truth and use what he said(its completely correct and best practice but may not suit this project for you). Just think, if you start designing networks that follow a standard and don't even know what the standard is, your teacher may grill the piss out of you.

I also agree with everyone else in the thread about it being a final level course, I had to do this EXACT lab for my senior project when I was in my associates program

 

[mavalpha]

[snip]
Include security and backup measures, and remote admin possibilities.
[snip]
what goes first switch or router?

Out of your intial post, these are the two lines that jumped out at me.
Backup doesn't mean a UPS in a closet, at least in my mind. In the event of a black-out, 99% of your network will be offline, including all of those labs, wireless AP's, and printers. The only computers that should have their own UPS's are servers, and it doesn't sound like your science wing is housing any such servers. The only thing that UPS would help against is an overloaded circuit, say from a janitor plugging in his 20-year old floor buffer into the same power outlet in the closet.
Back to the point: to me, your professor is asking for redundant networking capabilities- he may not mean dual NIC's in each computer, but at least some sort of fault-tolerance so that a faulty switch doesn't knock off 15 computers.

And now the part you aren't going to like:
If you still don't know the difference between a switch and a router, you are in over your head. A router almost invariably includes a firewall, meaning that each sub-network that is behind a router will be isolated from the rest of your subnetworks. One of your criteria was file-sharing across all nodes, which should have answered your question before you asked it. You only need one router to handle your internet connection (as already mentioned, most likely a 45mbps T3). That means that you shouldn't even be considering anything less than a gigE connection, forget about 10/100.

 

[Spartacus]

Would a Cisco switch that has 24 10/100/1000 ports be good? Why are there 3 speeds listed?

The instructor is not doing his/her job if you are asking this question while sitting down to do this project. Somthin' ain't right.

 

[computergeek13]

funny.... "has given us the task of designing a full network for a company." That sounds just like a capstone class at a couple of universities, not the first class.

its my 3rd quarter - my 2nd quarter i had an intro to OS class, and 2 GE classes math and comp. Now for this class, Network standards and protocol, this is our final. I wouldnt make it up and I know there is a ton of information i don't have - thats why i turned here.

I have spent 3 nights now until about 4 am reading as much as possible because the textbook for the class doesn't contain enough information.

 

[xphil3]

its my 3rd quarter - my 2nd quarter i had an intro to OS class, and 2 GE classes math and comp. Now for this class, Network standards and protocol, this is our final. I wouldnt make it up and I know there is a ton of information i don't have - thats why i turned here.

I have spent 3 nights now until about 4 am reading as much as possible because the textbook for the class doesn't contain enough information.

If I was in your shoes, idd be really pissed. Do what you can, I wouldn't read this post anymore because you will just end up putting in things that you don't understand.

If you're teacher says its bad, go to the dept. head and tell them about this ridiculous project he has you doing. One more thing, talk to other people in the class, feel them out to see what they are developing. If a lot of them are building out networks that you would consider advanced perhaps you didn't pay attention in class as much as you should have

 

[computergeek13]

Everything that Orinthical said is spot on, this may be to gauge your overall skill level and "stretching" the truth may not be something that you want to do in this case.

I will not be stretching the truth anything i include in my final project will be something i researched and can explain in detail. (i must include a 10 minute powerpoint presentation at the end as well, going over all hardware used, cabling, subnetting documentation, etc.)

To the OP, Orinthical just explained the core elements of a very specific standard topology, do you know what its called? I

I was going to use the star topology as the base fiber backbone, and use a sort of tree to feed the independant hallways

I also agree with everyone else in the thread about it being a final level course, I had to do this EXACT lab for my senior project when I was in my associates program

Well i guess its better i learn this now so i will be further advanced when i leave school. I still have 5 quarters left.

thank you for your help though im getting closer each day

 

[computergeek13]

If I was in your shoes, idd be really pissed. Do what you can, I wouldn't read this post anymore because you will just end up putting in things that you don't understand.

If you're teacher says its bad, go to the dept. head and tell them about this ridiculous project he has you doing. One more thing, talk to other people in the class, feel them out to see what they are developing. If a lot of them are building out networks that you would consider advanced perhaps you didn't pay attention in class as much as you should have

i'm at the top of my class - if you can believe that with my questions. i wonder how the others will do.

 

[computergeek13]

Backup doesn't mean a UPS in a closet, at least in my mind. In the event of a black-out, 99% of your network will be offline, including all of those labs, wireless AP's, and printers. The only computers that should have their own UPS's are servers, and it doesn't sound like your science wing is housing any such servers. The only thing that UPS would help against is an overloaded circuit, say from a janitor plugging in his 20-year old floor buffer into the same power outlet in the closet.

what he meant by backup measures was a backup server that the machines can access in a server room i imagine.

UPS i thought should be built into the main MDF and IDF rooms should they not? Don't you normally want those to have some sort of electrical protection from spikes etc.

 

[computergeek13]

Something more realistic for a private company would be a T3 though.

I decided on a the T3 line last night, i thkn 45 Mbps should be a good feed for the company.

Expand outwards with 2GB Trunks (2 fiber 1GB lines, trunked) to your other switches, each returning to the core switch.

i understand the trunk terms - with fiber there are two kinds of cabling. single mode and multi mode. I know multi mode can handle multiple signals. When you run fiber though, do you still need one for transmit and one for receive even if you use a multi mode fiber cable? or are they advanced now to where i just need 1 line for the transmit and receive to form athe trunk in between each closet.
I remember him telling us the book was a bit outdated when we touched on fiber lines.

And another question i haven't been able to find easily. the 1000 in 10/100/1000 stands for 1000 mbit right? or 1 gb? so when you are saying 2 GB trunks, is that gigabyte or gigabit?

The only reason I can think that he may be giving you something like this so soon, if this is indeed as early in your class as you say it is, is to gauge the classroom's knowledge level. If that is the case than you would be doing yourself an injustice by "pretending" to know more than you do, by seeking design help here or anywhere else. Level-setting is important for proper classroom development.

We have the last 3 weeks of class to finish this project - had it been given in week 3 due mid term i might be wary, but this is our final - so i don't think he can develop the classroom any further after the final week.


Believe it or not i am learning quite a bit - my textbook is a few years old and doesn't have up to date equipment in it at all. I have been looking up each term i do not understand and each piece of equipment so i will understand its use and perhaps the purpose for giving us this early is to display to us what we are getting into and prepare us for future jobs.

 

[Malk-a-mite]

i'm at the top of my class - if you can believe that with my questions. i wonder how the others will do.

Now all I want to know is what is the name of this school...

 

[ring.of.steel]

your doing all this and you don't know why 10/100/1000 is listed....

 

[computergeek13]

your doing all this and you don't know why 10/100/1000 is listed....

if i did i would not have asked for help - do you have any good sites that have basic explanations.

Im wondering how for example if i used a t3 line at 45 mbps in - switched it on a 1000 mb switch and ran fiber trunks to each halls closet - then ran fast ethernet cables to each room and put each switch in the office for the multiple machines in there.

if i only use 1000mb switch wouldnt the overhead be too much, should i use 100 mb switches in each room to balance the load on the main line?

or is it ok to use 1000 mb switches at every stage?

 

[Concentric]

if i only use 1000mb switch wouldnt the overhead be too much, should i use 100 mb switches in each room to balance the load on the main line?

or is it ok to use 1000 mb switches at every stage?

You can use gigabit switches everywhere and it won't slow down slower devices - the switches should automatically detect they are only 100mbit devices and run that port at 100.

 

[computergeek13]

ok here are 2 initial diagrams i had worked out today.
[img=http://img509.imageshack.us/img509/3082/topo1to9.th.jpg]

this is the main line entering the MDF - and the trunks branching out to each hallway.

I know Orinthical recommended 2 GB Trunks for these lines. are those the 1000baseFX lines?

For the wireless atrium - should i just run a ethernet line to the wireless router - or are there fiber wireless routers that accept a 1000baseFX input?

What router is commonly used in the MDF to accept a T3 line?

For the MDF and the IDF's should i use all the same switches? 24 port gigabit switches? do i need 48 port switches? is their an advantage to using one over the other?

[img=http://img516.imageshack.us/img516/8342/topo2uh4.th.jpg]

this picture is my diagram for the IDF that connect the offices -

Can these switches in the IDF's accept a 1000baseFX input and switch the output to fast ethernet 100baseT? or is their 1000baseT?

What is a good 12 port switch to put in each office that will connect the machines and printers?

That should keep me busy for the next few hours. I'll see what i can come up with on my own and compare with posters.

thanks for keeping the negative comments to a minimum i am trying what feels very overwhelming at the moment.

 

[Concentric]

For the wireless atrium - should i just run a ethernet line to the wireless router - or are there fiber wireless routers that accept a 1000baseFX input?

Why would you want a fiber WAP; the wireless is going to be like 11Mbit...

And why a wireless router not access points?

 

[computergeek13]

Why would you want a fiber WAP; the wireless is going to be like 11Mbit...

And why a wireless router not access points?

i thought a wireless router was an access point - ill have to look into that further.

 

[LHorstman]

if i did i would not have asked for help - do you have any good sites that have basic explanations.

Im wondering how for example if i used a t3 line at 45 mbps in - switched it on a 1000 mb switch and ran fiber trunks to each halls closet - then ran fast ethernet cables to each room and put each switch in the office for the multiple machines in there.

if i only use 1000mb switch wouldnt the overhead be too much, should i use 100 mb switches in each room to balance the load on the main line?

or is it ok to use 1000 mb switches at every stage?

I think one of the problems everyone is having with this is that this is a very basic networking concept. If your book is outdated and sucks, find a new on. You've got 3 weeks to learn this right? Try this. You need basics. Read quickly.

 

[computergeek13]

I think one of the problems everyone is having with this is that this is a very basic networking concept. If your book is outdated and sucks, find a new on. You've got 3 weeks to learn this right? Try this. You need basics. Read quickly.

ill stop at the bookstore tonight and refrain from posting until ive finished it. thank you.

 

[archivalbackup]

Am I the only one that thinks that this would be an awesome practical application to learn and apply skills even at the end of a first year course? Sure it is hard but I bet he is learning a ton. The thing that I have always missed while studying for my certifications is a practical 'in the real world' type of exercise.

Any thoughts on using VLANs for your floors / wings and a nice layer 3 switch at the core to do the inter-vlan routing?

 

[xphil3]

Am I the only one that thinks that this would be an awesome practical application to learn and apply skills even at the end of a first year course? Sure it is hard but I bet he is learning a ton. The thing that I have always missed while studying for my certifications is a practical 'in the real world' type of exercise.

Probably The problem seems to be that he doesn't know the basics and he is the top of his class. There is a problem with the teacher I guess. Don't get me wrong, I was doing shit like this before I even went into college, so I am perhaps a bit bias.

Any thoughts on using VLANs for your floors / wings and a nice layer 3 switch at the core to do the inter-vlan routing?

This was the original problem, he doesn't really understand those concepts. I asked a basic question relating to a collapsed core design(which someone recommended) and im positive that he didn't understand it(let alone the 3 layer model).

computergeek,

You got some reading to do, but remember.... don't just read. Read then APPLY. When you are finished bring this post back from the dead or create a new one and let us all know what you came up with

http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/index.htm <--excellent resource

Good luck man

 

[Malk-a-mite]

(let alone the 3 layer model)

3 layer model - in short form
http://www.mcmcse.com/cisco/guides/hierarchical_model.shtml


... and yes I was serious when I asked about the name of this school.

 

[jeffmoss26]

That cisco link is good, but the equipment seems outdated.
I think this would be a good project but you need the fundamentals down pat. Some of the questions being asked leave a lot to be desired. In the classes I am taking, we work mostly on the server end of things, but those in the class already know about routers, switches, IP addresses, subnets, etc. One of our entry level required classes was a lecture class on the nuts and bolts of basic networking. Even though I knew most of it, I felt that it was a good review before getting into the hands on administration. Also, I have that Networking for Dummies set and it is a great reference tool.
Now a few things based from your diagrams. There is no reason to have a 12 port switch in every office. The way I would do it, and I have done real networks, is to run all the cables back to one or more switches in the IDF. This means probably a 48 port switch in the IDF.

Jeff

 

[computergeek13]

Probably The problem seems to be that he doesn't know the basics and he is the top of his class. There is a problem with the teacher I guess. Don't get me wrong, I was doing shit like this before I even went into college, so I am perhaps a bit bias.

This was the original problem, he doesn't really understand those concepts. I asked a basic question relating to a collapsed core design(which someone recommended) and im positive that he didn't understand it(let alone the 3 layer model).

well this is my first networking class. i had an intro to OS class last quarter with a math and comp class. And my first quarter consisted of another math class with 2 other general education courses. it wasnt very hard to make the deans list with a 4.0 there. This has been my toughest quarter yet.

So perhaps it was out of line for me to state i am at the top of the class, i do know the labs we have done this year i have picked up quicker than others and i am carrying the best grade in the class for networking standards and protocols. However, the first 6 weeks of class we touched on switches for half of week 3, routers was week 4. I understood enough to continue reading but these concepts you feel i should have down, we never discussed.

I picked up the book recommended before and am reading as we speak. Just thought i would try and defend some of the negativity and keep my spirits up.

I refuse to turn in an assignment that was not thoroughly researched and that i do not understand 100%. I know i have to present this to the class at the end of the year and there will be questions from my dept head and instructor.

I am trying to learn this material as fast i can and i think i came to the right place. You all have a world of on-the-job expertise that i hoped i could feel free to ask these types of questions when i didnt understand a concept.

So thank you to those that have helped, those that doubt my performance, well there is nothing i can do. I cant imagine you think the class idiot or slacker would even put forth this much effort and could see an A student was trying his best to accomplish what seems an overwhelming task to a first year student.

With that i am headed back to reading.

 

[computergeek13]

3 layer model - in short form
http://www.mcmcse.com/cisco/guides/hierarchical_model.shtml


... and yes I was serious when I asked about the name of this school.

You are correct, i have do not know anything about Vlans, and the layer 3 switch my instructor touched on - its a switch (which normally operates on layer 2 ) that operates on layer 3 (the typical routing layer).

So it is essentially an intelligent router/switch? Our book has nothing on it, and he only mentioned it while we were covering switches. I remember that much but nothing more.

I am trying to search/read/research all these topics i do not understand from this thread before i post anymore about my updates to the project.

I am enrolled at ITT Tech. I am in my first year, 3rd quarter. I don't know why no one believes me. All i can say is i am trying hard to put all this together, and hope that i do well on it.

 

[computergeek13]

That cisco link is good, but the equipment seems outdated.
I think this would be a good project but you need the fundamentals down pat. Some of the questions being asked leave a lot to be desired. In the classes I am taking, we work mostly on the server end of things, but those in the class already know about routers, switches, IP addresses, subnets, etc. One of our entry level required classes was a lecture class on the nuts and bolts of basic networking. Even though I knew most of it, I felt that it was a good review before getting into the hands on administration. Also, I have that Networking for Dummies set and it is a great reference tool.
Now a few things based from your diagrams. There is no reason to have a 12 port switch in every office. The way I would do it, and I have done real networks, is to run all the cables back to one or more switches in the IDF. This means probably a 48 port switch in the IDF.

Jeff

thank you for your constructive criticism. I initially put those 12 ports in each office because the instructor asked that we "plan for future expansion" and i thought it would be easiest to just tap into those 12 ports rather than run a length of cable back to the IDF in the hallway.

The hallways are 200 feet long. I dont think that would matter though, since it calculates out to about 60m and Cat5e cable should be able to be run that long no prob.

 

[JDMs14]

I'm curious, what textbook did they supply you with?

 

[xphil3]

So perhaps it was out of line for me to state i am at the top of the class, i do know the labs we have done this year i have picked up quicker than others and i am carrying the best grade in the class for networking standards and protocols. However, the first 6 weeks of class we touched on switches for half of week 3, routers was week 4. I understood enough to continue reading but these concepts you feel i should have down, we never discussed.

I think that you are missing my point as well as most of the others that have posted comments a bit on what you consider the negative side. My point was, use what you were taught... many of the folks on these forums like to provide "over engineered" or "advanced" concepts that probably span outside the scope of your class as well as the project. When I was in school many of my teachers would penalize students that would go beyond what they were asking for(it was hard for me to deal with).

I picked up the book recommended before and am reading as we speak. Just thought i would try and defend some of the negativity and keep my spirits up.

I think ill apologize for everyone in this thread if you felt negativity, I can assure that there was none directed towards you. What most of us can't understand is why your teacher is asking you to do such a project and you were never taught about certian basics(asking questions about port speeds on a switch, etc). So once again, I apologize for any "negativity".

I am trying to learn this material as fast i can and i think i came to the right place. You all have a world of on-the-job expertise that i hoped i could feel free to ask these types of questions when i didnt understand a concept.

You came to the right place, just take what EVERYONE says with a grain of salt.

So thank you to those that have helped, those that doubt my performance, well there is nothing i can do. I cant imagine you think the class idiot or slacker would even put forth this much effort and could see an A student was trying his best to accomplish what seems an overwhelming task to a first year student.

With that i am headed back to reading.

I don't think any of us doubt your performance, we just know that you have some work ahead of you. Like I said before, I really would like to see what you come up with before you hand it in and as always Im sure that you want some criticism

take care bud

 

[computergeek13]

thank you xphil, that helps.

as far as the port speeds - i was a little confused with gigabit, we didnt discuss that but in passing mention. I have grasped that now and connected it with the 10/100 speeds.

i have a few weeks before its due, i hope to be done researching and reading by next week at some point. Have a design done a few days thereafter, and ill post what i have.

the last week will probably be spent on subnet documentation and a powerpoint presentation.

 

[Boscoh]

Look into Layer 3 switches vs Layer 2 switches. Layer 3 switches have routing abilities as well. I think you'll find that this might change your design a little bit.

If you want to learn how to do this stuff well, my recommendation is to go out and buy a book around CCDA. Sybex and Cisco Press are two publishers that generally produce good quality books around this. CCDA will help you learn how to design networks.

Your journey should include looking at reference designs like the ones listed here as well:
http://www.cisco.com/en/US/netsol/ns656/networking_solutions_program_home.html